Colitis is inflammation of the colon that can lead to symptoms like abdominal pain, gas, dehydration, blood in the stool, and alternating periods of watery diarrhea and constipation.

It may be triggered by changes in the immune system, but it can also result from bacterial or viral infections.

Treatment for colitis is managed by a gastroenterologist, proctologist, or general practitioner depending on the cause. It usually involves medication, a healthy diet, and, in some cases, surgery.

Patient reporting abdominal pain to doctor

Symptoms of colitis

The most common symptoms of colitis include:

Abdominal pain or cramping
Alternating diarrhea and constipation
Mucus in the stool
Blood in the stool
Fever
Chills
Dehydration
Excess gas
Loss of appetite
Fatigue

In some cases, colitis can also cause symptoms outside the digestive system, such as joint pain, eye inflammation, or skin conditions like erythema nodosum and pyoderma gangrenosum.

Anyone with symptoms of colitis should see a general practitioner, gastroenterologist, or proctologist for diagnosis, to determine the cause, and to begin treatment as soon as possible.

Confirming a diagnosis

Colitis is diagnosed by a gastroenterologist or proctologist through a review of symptoms, a physical exam, and lab or imaging tests.

Possible tests include stool analysis, ultrasound, CT scan, MRI, colonoscopy, or sigmoidoscopy. Blood tests may also be ordered, such as perinuclear antineutrophil cytoplasmic antibody (P-ANCA), anti-Saccharomyces cerevisiae antibodies (ASCA), and carcinoembryonic antigen (CEA).

Possible causes

The main causes of colitis include:

Viral, bacterial, or parasitic infections
Food intolerances or allergies
Blocked blood vessels in the intestine
Genetic or autoimmune factors

Colitis may be acute or chronic, and symptoms vary depending on the cause. A medical evaluation is important for proper diagnosis and treatment.

Is colitis serious?

If left untreated, colitis can become serious and lead to complications such as intestinal bleeding, fistulas, narrowing of the intestine, or even colorectal cancer.

For this reason, anyone with signs of colitis should consult a gastroenterologist to confirm the diagnosis, identify the type and severity, and start treatment promptly.

Types of colitis

The types of colitis that can present include:

1. Ulcerative colitis

Ulcerative colitis is inflammation of the lining of the large intestine, marked by multiple ulcers in the intestinal wall that cause significant discomfort.

Ulcers may appear throughout the colon, in isolated areas, or in the lower portion. Other symptoms include diarrhea with mucus and blood, abdominal pain, and fever.

Its exact cause is not fully understood but may involve genetic factors, immune system changes, and bacterial or viral infections that alter gut flora. When diagnosed early, treatment can control inflammation and prevent complications. Without treatment, ulcerative colitis increases the risk of colorectal cancer.

2. Pseudomembranous colitis

Pseudomembranous colitis is caused by Clostridium difficile, a bacteria normally found in the intestine. When it multiplies excessively, it releases toxins that damage the intestinal lining and cause inflammation.

This type of colitis is often linked to antibiotic use, such as amoxicillin or azithromycin, which disrupt the balance of gut bacteria and allow Clostridium difficile to overgrow.

3. Nervous colitis

Nervous colitis, also known as irritable bowel syndrome (IBS), is more common in young adults and is associated with psychological factors like stress and anxiety. These conditions make the intestine more sensitive and prone to inflammation.

Symptoms include abdominal pain, bloating, and excess gas.

4. Ischemic colitis

Ischemic colitis develops when blood flow to the intestine is reduced or blocked, often due to fat buildup in the blood vessels.

It can cause ulcers, inflammation, abscesses, swelling, and increase the risk of intestinal bleeding. This type of colitis is often linked to conditions such as diabetes, smoking, dehydration, heart failure, atherosclerosis, thrombosis, or systemic inflammatory response syndrome.

5. Microscopic colitis

Microscopic colitis can only be diagnosed with a biopsy taken during colonoscopy.

Although the intestine may appear normal during the procedure, inflammation is seen under the microscope when analyzing intestinal cells. The exact cause is unclear, but several combined factors may contribute to its development.

6. Infectious colitis

Infectious colitis is caused by viruses such as norovirus, rotavirus, adenovirus, or cytomegalovirus, parasites like Entamoeba histolytica, or bacteria including Campylobacter jejuni, Salmonella, Shigella, Escherichia coli, Yersinia enterocolitica, or Mycobacterium tuberculosis.

Certain sexually transmitted infections may also cause colitis, such as gonorrhea, chlamydia, herpes simplex types 1 and 2, or syphilis.

Typical symptoms include acute diarrhea, stools with pus, blood, or mucus, fever, and abdominal pain.

7. Allergic colitis

Allergic colitis is more common in infants and usually related to an allergy or hypersensitivity to proteins in breast milk, cow’s milk, or infant formula.

It can cause symptoms such as reflux, abdominal pain, blood in the stool, and irritability.

Treatment options

Treatment for colitis is prescribed by a doctor and varies according to the cause.

1. Diet

Diet is an important part of managing colitis. It helps reduce complications, relieve symptoms, and improve nutrient absorption.

There is no single diet for colitis, but a nutritionist may recommend a balanced eating plan with lean meats, fruits, vegetables, healthy fats, and natural seasonings.

Raw foods should be avoided, and food should be chewed well. If symptoms persist, a liquid diet may be recommended. Probiotic-rich foods like yogurt and kefir can also help restore intestinal balance.

2. Medications

Medications may be prescribed to relieve symptoms, control inflammation, or fight the infection causing colitis.

The main options include:

Pain relievers, such as acetaminophen
Anti-inflammatory drugs, such as ibuprofen
Antibiotics, such as metronidazole or vancomycin
Antidiarrheal drugs, such as loperamide
Corticosteroids, such as prednisone or prednisolone
Immunosuppressants, such as azathioprine or cyclosporine
Biologic agents, such as infliximab, adalimumab, or ustekinumab

A nutritionist may also recommend multivitamin supplements to improve nutritional status.

3. Surgery

Surgery is considered when medications and dietary changes are not effective. It may involve removing part or all of the colon or rectum and is usually reserved for severe cases with irreversible damage.

4. Home remedies

Home remedies for colitis may help ease symptoms such as abdominal pain, gas, chills, and dehydration. They should be used only as a complement to medical treatment, not as a replacement.

One option is fresh apple juice, which can be consumed several times a day. To prepare it, blend fresh apples and drink right away.

Colitis: Symptoms, Diagnosis, Causes, Types & Treatment